The cap stays securely closed thanks to a robust silicone seal, and opens for sipping with a simple twist. The cap is top-rack dishwasher safe. Double-walled stainless steel construction keeps the Wide's contents hot for up to 8 hours or iced for up to 24 hours. There's no liner, just an electro-polished interior that prevents flavors from lingering and makes cleaning easy. The wide-mouth design makes adding ice and cleaning easy, and is compatible with most backcountry water filters.